Quasinormal modes and non-linear behaviour

          @misc{ pirsa_PIRSA:24070091,
            doi = {10.48660/24070091},
            url = {https://pirsa.org/24070091},
            author = {May, Taillte},
            keywords = {},
            language = {en},
            title = {Quasinormal modes and non-linear behaviour},
            publisher = {Perimeter Institute},
            year = {2024},
            month = {jul},
            note = {PIRSA:24070091 see, \url{https://pirsa.org}}
          }
          

Abstract

Gravitational waves from black hole binary mergers can tell us a lot about the physics of the system. At the late part of the graviational wave signal, GR predicts the presence of characteristic frequencies (called quasinormal modes) in the signal. Measuring multiple quasinormal modes is a strong consistency test for GR. Here we probe the regime where a signal can be described entirely by quasinormal modes. We consider a higher order effect, where the remnant black hole is absorbing some radiation and so has a changing mass and spin. We test the contribution of this effect to the signal in a physically relevant scenario. We find evidence that this effect causes other mode excitations as well as a changing frequency contribution.